Electric snap switch



March 17, 1931. R. A. MILLERMASTER 1,796,854

ELECTRIC SNAP SWITCH Filed Oct. 5, 1929 2 Sheets-Sheet 1 A TTORNEY March 17, 19315 R. A. MILLERMASTER 1,796,854

ELEGTRIC SNAP SWITCH F'ledOCt. 5, 1929 2 Sheets-Sheet 2 IN VEN TOR.

Imm/MMM ATTORNEY Patented Mar. 17, 193.1.

UNITED STATES' PATENT OFFICE RALPH A. MILLEEMASTER, E MILWAUKEE, WISCONSIN, ASSIGNOR To CUTLER- HAMMER, INC.. 0E MILWAUKEE, WISCONSIN, A CORPORATION 0E DELAWARE ELECTRIC SNAP SWITCH This invention relates to improvements in electric snap switches.

An object of the invention is to improve andsimplify the construction and assemblyoic the parts of switches .of the aforementioned character.

Another object is to provide a novel construction and. arrangement of parts whereby the life or durability of switches of the afore-v mentioned character is greatly increased. Another object is.to.provide a novel form of snap switchwhich is Substantially noiseless inoperation.

Another object is to provide a novel inter.- locking arrangement of the switch parts whereby the number of parts and the timerequired to assemble the same are reduced to a minimum. y

Another object is to embody the aforementioned features in high grade flush switches of the enclosed type.

Various other improvements inthe details -of construction of the switch elements will be apparent or will be specifically pointed out in the course vot the following description.

The accompanying drawings illustrate certain preferred embodiments of the invention, which will now be described, it being understood that the invention is susceptible of embodiment in other forms without departing from the scope of the appended claims.

In the drawings, Fig. 1 is a top plan view of a single pole toggle flush switch of the enclosed type embodying my invention, the insulating cover member and the supporting lugs or elements having been omitted for purposes of illustration.

Fig. 2 is an enlarged vertical sectional view on the line 2-2 of Fig. 1.

Fig. 3 is a similar view on the broken line 3-3 of Fig. 1.

Fig. 4 is a view similar to Fig. 1, but showing a switch of the double poletype.

Fig. 5 is a view of the switch shown in Fig. 4, with the insulating cover member and one 'of the supporting lugs in position.

Fig. 6 is a view partly in plan and partly in section showing a carrier for a single pole switch, and. illustrating the manner of attaching and insulating the movable contact elements with respect thereto.

Fig. 7 is a plan view of the movable contact elements and certain of the associated p arts prior to attachment thereof to the carrier.

Fig. 8 is a plan view of a carrier adapted for use in a double pole, three-way or fourway switch. Fig. 9 is an enlarged top plan view of the insulating base of a single pole switch with all of the switch parts omitted for purposes of illustration.

Fig. 10 is a bottom plan view of the insulating cover member which is complementary to the base shown in Figs. 1 and 9.

Fig.. 11 is a top plan view similar to Fig. 1, but with the insulating cover member and one of the supporting lugs in position.

Fig. 12 is a detail perspective view of one of the combined stationary contact and terminal members of the switch.

Fig. 13 is a similar view of another of the combined stationary contact and terminal members of the switch.

Fig. 14 is a plan view of a stamped sheet `metal blank which may be employed in formation of the switch frame.

Fig. 15 is a perspective view of the Switch 'insulating base of a single pole snap switch embodying my invention, said base having a flat upper face 21 and a flat lower face 22, the end portions of the lower face being offset-upwardly as indicated at 23, 24 (Fig. 2)

as is customary in this type of switch. Base 2O is relatively deeply recessed from the upper face thereof, as best illustrated at 25 and 26 in Figs. 2 and 9,-the recess 25 with its arcuate depression 27 being adapted to ac? commodate the switch frame and actuating mechanism and the recess 26 being adapted to accommodate the oscillatable bridging GOD,- tact of the switch.

Extending throughout the depth of recess 25 and at opposite ends thereof are alined channels 28 and 29, and extending upwardly a short distance from the bottom wall of recess 25 are pairs of integral shoulders or abutments 30 and 3l, the opposed walls 32 and 33 of which are convergent to forni a pair of dovetail recesses at opposite ends of the insulating base.

Adapted to seat rather snugly within said dovetail recesses are a pair of correspondingly shaped soft or live rubber cushions or blocks 34 and 35, said blocks being of identical shape and size and one of the same being illustrated in detail in Fig. 16. Said blocks are preferably formed by cutting into sections of the desired thickness a strip or bar of extruded rubber of the required shape in cross section,-care being exercised in the cutting operat-ion to insure substantial parallelism of the cut faces of the blocks. The opposed smaller faces of the rubber blocks are providedwith arcuate cut away portions or vertical channels 34, 35a for a. purpose to be described. j

The switch frame, which is preferably made from a stamped sheet metal blank of the form illustrated in Fig. 14, comprises a flat base port-ion 36 having spaced substantially rectangular' perforations 37 and 3S, and the ends of said base portion being of reduced width, as indicated at 39 and'40, to tit within the aforementioned vertical channels 28 and 29 in base 20. The blank illustrated in Fig. 14 is bent along the dotted lines 41 and 42 to provide the frame arms 43 and 44 extending up\\'a1dly at right angles to the base 36. Y

As shown the frame arms are provided with relatively large perforations 45 and 46 of substantially inverted triangle shape, whereas the frame blank is punched out as indicated at 47 (Fig. 14) -to provide a relatively wide cut away portion extending entirely across the frame base and upwardly along the frame arms, thus leaving relatively narrow angular portions 48 and 49 integral with the frame arms or sides.

The frame arms 43 and 44 are of reduced width above the perforations 45, 46,-said reduced portions being provided with alined circular openings 50 and 51 to receive the headed pivot pin 52 (Figs. 2 and 3). Above the openings 5() and 51 the frame arms' are still further reduced in width as shown at 53 and 54,-right angled shoulders 55 and 56 being preferably provided between said reduced portions 43, 53 and 44, 54.

Pivotally supported by the pin 52 between the arms of the switch frame is a flat stamped sheet metal toggle lever or rocker 57, said lever having an upwardly extending arm 58 which is notched or otherwise suitably formed as indicated at 59 to provide a proper interlocking connection between the same and the insulating handle portion 60 which is molded thereabout. Said handle portion is of only slightly less width than the space between the frame arms, so that the lever is constrained to move in a constant plane, thatA is, without substantial lateral movement or.- .wobbling Lever 57 is provided withv relatively widely divergent curved arms or extensions 61 and 62 the ends of which are adapted tomove alternately through the perforations 37 and 33 in the frame base and into engagement with the upper surfaces of the rubber blocks 34 and 35, respectivelv`, whereby oscillatory movement of lever 57 in each direction is vieldably limited.

Also projecting from lever 57 at a point intermediate-the ends of arms 61 and 62 is an arm 63 the end of which is-of rounded or spherical form as indicated -at'64, said end being adapted to cooperatively engage the upper closedand s'lightlydepressed end 65 of a metallic cylinder4 or cup 66 whichpsubstantially encloses a spiral compression spring 67 which' is interposed between the lever 57 and the contact carrier 68 of the switch. y

Contact carrier 68, as best shown in Fig. 6 comprises a fiat punched sheet metal member of substantially bail form, said carrier being adapted to embrace the base and the lower portions of the sides or arms of the switch frame. The adjacent inner edges of said carrier are provided with alined projections 69 and 7 O the lower edges 71 and 72 of -which are adapted to bear upon the con-v vergent walls of perforations 45 and 46 in the frame upon assembly of the parts.

To facilitate assembly of the carrier with respect to the frame and to provide for assembly of these parts by hand, the former is provided beneath the bearing edges 71, 72 thereof with outwardly stepped or cut away portions 73 and 74. It will be apparent that bythis arrangement either of the projections 70 or 69 and the respective stepped portions therebeneath may be inserted bodily into one or the other of the openings 45, 46 in the frame, such insertion requiring a -slight tilting of the carrier in its own plane, and the cut away portions 73, 74 being adapted to accommodate the portions 48 or 49 of the frame arms.

Thereupon the carrier may-be tilted in the opposite direction in its own plane to bring the other projection 69 or 70 into alinement with the other perforation 46 or 45 in the frame arms. r1`he carrier is then shifted axially to bring each of the lower edges 71 and 72 into cooperative engagement with the respective bearing openings. When assembling the parts in the manner just described it is preferable to engage the lower end of vspring 67 with the abutment 75 provided on the carrier, the cylinder or cup 66 at the same time being held in an angular relation to provide for accommodation of the edge portions 76 of the carrier within the diametrically opposed slots or notches 77, 78 in the lower end of the cylinder as the spring is compressed by the assembling operation. Thus the carrier Willbe securely held in operative relation to the frame' by Aa simple interlocking engagement of the parts.

As best shown in Fig. 6 the carrier 68 is '10 provided with a'pair of integral projections 79 and 80 the inner ends of which are provided with shoulders 81 and 82 which are adapted to interlock with thev outwardly oset portions 83 and 84 of a substantially elliptical metal washer or plate 85. A duplicate but reversely arranged outer metal washer 86 is likewise provided, said washers having nested theebetween the relatively larger substantially rectangular insulating plates 87 and 88,-the oppositely offset portions of said insulating plates being adapted to extend into correspondingly shaped openings in the resilient contact 'elements 89 and. 90, which are of usual form. With the ends of projections 79 and 80 riveted over as shown in Fig. 6 the y contacts are rigidly secured to the carrier but in properly insulated relation with rep spect thereto.

'With the parts assembled upon the switch a0 frame in the manner aforedescribed the latter may be inserted into the recess in base 20 until it rests upon the soft rubber blocks 34 and 35, the projections 39 and40 on the frame base being positioned between the opposed walls of end channels 28 and 29 as aforestated.

Located at one corner of the base 20 and upon the upper face 21 thereof is a terminal member 91, said member having a tapped opening 92 for cooperation with. a screw 93 penetrating an opening 94 in the base whereby the former is rigidly secured to the latter. Member 91 is provided with the usual tapped opening 95 for cooperation with the shank of a binding screw 96,-base 20 being provided with a cavity to accommodate said inding screw. Integral with member 91 and extending downwardly and then inwardly with respect thereto is a portion 97 (F ig.`12) which is shaped asindicated at 98 to form the lower stationary contact of the switch. The terminal member 99 at the other end of base 20 is secured to the latter in a similar manner,- said member having a slightly upwardly and then inwardly projecting integral portion 100 which is shaped as indicated at 101 .to form the upper stationary contact of the switch.

As best shown in Fig. 3 the arm portions 43, 53 and 44, 54 of the switch frame extend a considerable distance above the base 20, and said portions are adapted to be cooperatively engaged by the walls of correspondingly shaped notches 102, 103 and 104, 105 on the under face of an insulating cover member 106. Said cover member is provided with suitably formed cavities or recesses 107, 108 to accommodate the actuating lever and the movable contacts of the switch, and a notch or groove 109 is provided to accommodate the upwardly projecting portion 100 of sta;- tionary contact 101. (over member 106 is likewise provided with an elongated rectangular opening 110 to permit oscillatory movement of theinsulating handle portion 60 of the actuating lever while acting to prevent Y substantial lateral movement of the latter.

The ends of cover member 106 are formed as shown at 111 and 112 to expose the binding screws 96, whereby wiring of the switch islacilitated. Also as shown in Fig. 10 the but the same preferably comprise integral plaster engaging portions 123, 124, as shown in Figs.'2, 5 and '11.

As will be understood the arrangement is v preferably such that upon complete assembly of the switch and casing parts the frame will be pressed to a certain degree into engagement withthe rubber blocks, whereas the inherent resiliency of the latter provides a sort of floating support for the switch mechanism. By this means I provide for self-adjustment of the movable contacts with respect to the stationary contacts of the switch. Moreover, by arranging the parts in a manner to utilize the yielding faces of the rubber blocks asy abutments for the contact carrier and actuating lever of the switch, I haveprovided a switch mechanism which is substantially noiseless in operation, and in which the life or durability of the cooperating switch parts is very greatly increased.

As best illustrated in Fig. 11 the insulating base and cover member may be shaped to give a pleasing appearance and the cover member may be further provided with suitable decorative paneling and stippling, asi

lshown at 125.

The double pole switch illustrated in Figs. i 4, 5 and 8 is in man respects substantially like that aforedescri ed. However, in this case the insulating base and cover membersl are somewhatfwidened and suitably recessed to accommodate a pair of movable contacts 89, 90' at each side thereof, the carrier 68'* being provided with two pairs of projections l79, 80Il for support ofy said contacts. The

4oppositely arranged terminal members 91",

99b are respectively provided with lower and upper stationary contact portions 98", 101". The switch mechanism is assembled with respectto the insulating casing in the manner aforedescribed, and the insulating cover member may be suitably decorated as shown at 125.

What I claim as new and desire to secure by Letters Patent is:

I 1'. In an electric snap switch, in combinaJ tion, a cup-shaped insulating base having-a recess therein, a soft rubber cushion resting upon the' bottom wall of said recess, a substantially U-shaped metal frame having its flat bottom surface resting loosely upon said rubber cushion, and an insulating cover member for said base, said cover member'having means engaging the arms of said U-shapedl frame to assist in positioning the latter and to retain the same in assembled relation to said base.

2. In an electric snap switch, in combination, a cup-shaped insulating base having a recess therein, a soft rubber cushion resting upon the bottom wallv of said recessa substantially U-shaped metal frame having its flat bottom surface resting loosely upon said rubber cushion, an insulating cover member for said base, said cover member ha means engaging the arms of said U-shaped frame to assist in positionin the latter and to retain the same in assem led relation to said base, supporting means for said base, and common means for1securing said base and cover member to each other and to said supporting means.

3. In an electric snap switch, in combination, a cup-shaped insulating base having a recess therein, a pair of soft rubber blocks resting upon the bottom wall of said recess in spaced relation toeach other, a substantially U-shaped metal frame the base portion of which is adapted to rest upon said rubber Y blocks and the arms of which extend upwardly beyond said insulating base, an insulating cover member for said base, said cover member having notches the walls of which engage the arms of said frame to hold the latter against substantial upward or horizontal movement relative to said insulating base,l a contact carrier pivoted to said frame and oscillatable between the opposed faces of saidrubber blocks, an operating lever pivoted to saidframe and extending outwardly through said cover member, and a coiled comopposed longitudinally spaced walls of said recess having alined vertical channels and the base portion of said frame having projections to be positioned between the side walls of said channels, an insulating cover member for said base, said cover memberhaving notches Athe walls of which engage the arms-of said `frameto hold the latter against substantial upward or horizontal movement relative to' said insulating base, a contact carrier pivoted to said frame and oscillatable between the opposed faces of said rubber blocks, an operating lever pivoted to said frame and extending outwardly through said cover member,and a coiled compression spring interposed between said lever and said contact carrier.

5. ,A substantially noiseless snap switch of the flush type com rising a two-part enclosing casing of mol ed insulating material, a cavity within said casing, a plurality of soft rubber cushions located in spaced relation to each other upon one wall of said cavity, a substantially U-shaped sheet metal frame engaged by another wall of said cavity and held in pressing engagement with said rubber cushions, a flat stamped sheet metal contact carrier pivotally supported by said frame and osc latable from one extreme position to the vother into alternate engagement with the opposed faces of said rubber cushions, an actuating lever pivotally supported by the arms of said frame, said lever having elon-k gated projections uponI opposite sides of the pivot oint thereof, the base portion of said frame aving erforations to permit passage of said projectlons therethrough into engage- Jment with said rubber cushionsjto thereby yielda-bly limit oscillatory movement of said lever, and a coiled compression spring interposed between said lever and said contact carrier to effect snap movements of the latter upon predetermined movements of the former.

6, In an electric snap switch, in combination, a stamped sheet metal frame of substantially vU-shape in cross section, the upwardly extending` arms of saidframe each having a relatively large perforation forming a closed bearing, the material of said frame being cut away beneath each perforation in conformity with the latter and across the base of the frame, a Hat stamped sheet metal contact carrier of substantially U-shape iso adapted to embrace said frame, the adjacent 'inner edges of said carrier having alined rojections adapted for cooperation with the earings in said frame, the material of said carrier being cut away beneath said projections in outwardly stepped relation to provide portions which are readily insertable individually Within either of said bearing openings upon tilting of said carrier, whereupon said carrier may be swung in its own plane to provide for alinement of the opposite projection and its cooperating bearing, said car-l rier being shiftable axially with respect to the frame t0 bring the parts into assembled relation, a rocklever pivoted to the frame above the carrier, and a coiled compression spring interposed between one end of said lever and said carrier to retain the latter in assembled relation to the frame.

7. lln an electric snap switch, in combination, a stamped sheet metal frame of substantially U-shape in cross section, the upwardlyJ extending arms of said frame each having a relatively large erforation of substantially inverted triang e shape forming a closed bearing adjacent to the lower end thereof, the material of said frame being cut away beneath each perforation in conformity with the latter and across the base of the frame, a flat stamped sheet metal contact carrier of substantially U-shape adapted to embrace said frame, the adjacent inner edges of said carrier having alined projections adapted for cooperation with the bearings in said frame, the material of said carrier bein cut away beneath said projections in outwar ly stepped relation to provide portions which are readily insertable bodilyv within either of said bearing openings upon tilting of said carrier, whereupon said carrier may be swung in its own plane to provide for alinement of the opposite projection and its cooperating bearing, said carrier being shiftable endwise with respect to the frame to effect engagement of both projections with their respective bearings, the vertical edges of said stepped portions being adapted to engage the outer surfaces of the frame arms to restrain said carrier against further axial movement, a toggle lever pivotally supported between the arms of the frame above said carrier, and a coiled compression spring interposed between the lower end of said lever and said carrier to retain the latter in assembled relation to the frame and to eect snap movements of said carrier from one extreme position to the other upon predetermined movements of said lever.

8. In an electric snap switch, the combination with a sheet metal frame of substantially U-shape in cross section, the upwardly extending sides of said frame having relatively large alined perforations forming closed bearmgs, of a Hat stamped sheet metal contact carrier of substantially bail form adapted to embrace the bottom and sides of said frame, said carrier having alined inward in its own plane to bring the other projection into alinement with its cooperating bearing opening and said carrier being shiftable axially with respect to the frame to bring each` of the upper stepped edges of said projections into pivotal engagement with said bearing openings, the vertical portions of said stepped edges cooperating with the frame sides to restrain said carrier against further axial movement in either direction, a toggle lever pivotally supported above said carrier, and a spiral compression spring interposed between one end of said lever and said carrier. 9. In anelectric snap switch, the combina.- tion with a sheet metal frame of substantially U-shape in cross section, the upwardly extending sides of said frame having relatively large alined perforations forming closed bearings, of a flat stamped sheet metal contact carrier of substantially bail form adapted to embrace the bottom and sides of said frame,

said. carrier having alined inward projec-V v tions the lower edges of which are arranged in outwardly stepped relation whereby either of said projections may be fully inserted into one of said bearing openings, said carrier being thereupon tiltable in its own plane to bring the other projection -into alinement with its Vcooperating bearin opening and said carrier being shiftable axially with respect to the fra-me to bring each of the upper stepped edges of said projections into pivotal j engagement with said bearing openings, the* vertical portions of said stepped edges cooperating with the frame sides to restrain said carrier against further axial movement in either direction, a toggle lever pivotally supported above said carrier, a spiral compression spring interposed between one end of said lever and said carrier, the base of said frame being cut away to accommodate said spring and the bottom portion of said carrier, and a cylindrical metal member substantially enclosing said spring, said member having a closed and indented end engaged by said lever the other end of said member having alined notches for sliding engagement withsaid carrier.

10. In an electric snap switch, the combination with a sheet metal frame of substantially U-shape in` cross section, the upwardly extending sides, of said frame having relatively large alined perforationsy forming closed bearings, of a ilat stamped sheet metal Contact carrier of substantially bail form adapted to embrace the bottom and sides of said frame, said carrier. having alined inward projections the lower edges of which are arranged in outwardly stepped relation whereby either of said projections may be f ully inserted into Aone of said bearing openings, said carrier being thereupon tiltable 1n its own plane to bring the other projection into alinement with its cooperating bearing o ening and said carrier being shiftable axlally with respect to the frame to bring each of the upper stepped edges of said projectlons into pivotal engagement with said bearing openings, the vertical portions of said stepped edges cooperating with the frame sides .to restrain said carrier against further axial movement in either direction, a toggle lever pivotally supported above said carrier, a sp1- ral compression spring interposed between one end of said lever and said carrier, the base of said frame being cut away to accommodate said spring and the bottom portlon of said carrier, and a cylindrical metal member substantially enclosing said spring, said member having a closed and indented end engaged by said lever, the other end of said member having alined notchesfor sliding engagement with said carrier, said membercooperating with said frame to positively 1n1- tiate movement of said carrier from each extreme position to the other. A

nation with a lmolded insulating base having a main recess, the bottom wall of said recess having vertical shoulders or abutments forming relatively shallow dove-tail recesses at op osite ends of said base, a pair of soft ru ber blocks snugly fitting within said last mentioned recesses and held against movement in a given plane by the angular walls of the latter, said blocks extending a substantial distance above the shoulders which form said recesses, a sheet metal frame the'base of which is adapted toA rest upon said blocks, a flat stamped sheet metal contact carrier depending from said frame and oscillatable from one extreme position to the other into en agement with the respective rubber bloc s, a

molded insulating cover member for saidv base, and means on said cover member adapted for interlocking engagement with said frame to retain the latter 1n assembled relation to said base. l

1 2. In an electric snap switch, in combination, a stamped sheet metal frame of substantially U-shape in cross section, the upwardly extending arms of said Iframe each having a relatively large perforation forming a closed bearing, the material of said Y frame bein cut away beneath each perforation in con ormity with the latter and across the base of the frame, a ilat stamped sheet metal contact carrier of substantially U-shape adapted to embrace said frame, the adjacent inner edges of said carrier having alined projections adapted for cooperation with the bearings in said frame, the material of said carrier being cut away beneath said projections in outwardly stepped relation to provide portions which are readily insertable in dividually within either of said bearlng openings upon tilting of said carrier, whereupon said carrier may be swung in its own plane to provide .for alinement of the opposite proj ection and its cooperating bearing, said carrier being shiftable axially with respect to the frame to bring theparts into assembled relation, a rock lever pivoted to the frame above the carrier, a coiled compression spring interposed between one end of said-lever and said carrier to retain the latter in assembled relation tothe frame, an insulating base having a recess, a pair of soft rubber blocks located in spaced relation to each other upon the bottom wall of said recess, said metal frame resting upon said blocks and the arms of the former projecting upwardly beyond said insulating base, an insulatin cover member having notches the walls 'o which engage the arms of said frame to retain the latter in assembled relation to said base, a pair of supporting lugs for said base, and common means for securing said base and cover member to each other and'to said supporting lugs.

13. In an electric snap switch, the combination with a sheet metal frame of substantially U-shape in cross section, the upwardly extending sides of .said frame having relatively large alined perforations formingl closed bearings, of a fiat stamped sheet m'etal contact carrier 'of substantially bail form adapted to embrace the bottom and sides of said frame, said carrier having alined inward projections the lower edges of which are arranged in outwardly stepped' relation whereby either of said projections may be fully inserted into one of said bearing openings, said carrier being thereupon tiltable in its own plane to bring ythe other projection into alinement with its cooperating bearing opening and said carrier being shiftable axially with respect to the frame to bring. each of the upper stepped edges of said projections into pivotal engagement with .said bearing openings, the vertical portionsfof saidstepped edges cooperating with the frame sides to restrain said carrier against further axial movement in either direction, a toggle lever pivotally supported above saidcarrier, a spiral compression spring interposed between one end of said lever and said carrier, the base of said frame being cut away to `accommodate said spring and the bottom portion of said carrier, a

cylindrical metal member substantiall closing said spring, said member havmg a closed and indented endengaged by said lever, the other end of said member having alined notches for sliding engagement with said carrier, and a longitudinally divided two-part insulating casing having a pair of spaced soft rubber blocks upon which said switch frame is adapted to seat, saidblocks -each having an ularly arranged faces with which said togg e lever and said carrier are respectively .adapted to engage to thereby yieldably limit the oscillatory movements of said parts.

14. A flush snap switch comprising a hori-A zontally divided two-part insulating casing providing a cavity, a switch mechanism lo cated within said cavity and clamped in position by said casing parts, soft rubbercushioning means interposed between one of said lcasing parts and said switch mechanism to provide a floating support for the latter, switch operating means projecting' through the other of said casing parts, and wiring terminal means readily accessible from the eX- terior of said casing.

15. A snap switch of the toggle type adapted for iiush mounting, comprising a recessed molded insulating base, stationaryv contact and terminal members secured to said base at thecorners thereof, soft rubber cushioning means seated upon the bottom wall of said recess, a switch mechanism comprisingv a metal frame seated upon said cush- -ioning means, said framehaving parts pro` jecting above said base, a molded insulating cover member for said base, said cover member having interlocking engagement with the projecting parts of said frame, a toggle'actuating lever projecting through said cover member, and means for rigidly securing said Y base and cover members to Ieach other whereby said vframe is held in proper position, the 'i a substantially U-shaped metal frame the liiat j base portion of which is adapted to rest loosely upon said rubber blocks and the arms of which extend upwardly beyond said ini sulating base, a member extending across the upper face of said insulating base, said member having notches the walls of which engage the projecting arms of said frame to -hold the latter against substantial upward or hori-A zontal' movement relative to said insulating base, a flat punched sheet metal Contact carrier pivotally supported directly. by said frame and oscillatable between the opposed faces of said rubber blocks, an operating lever pivoted to said frame and extending outwardly through an opening in the member aforementioned, and a coiled compression spring interposed between said lever and said contact carrier. y

In witness whereof, I have hereunto subscribed my name.

RALPH A. MILLERMASTER. 

